Damper assembly

ABSTRACT

A damper assembly includes a housing positionable between refrigerator compartments operable at different temperatures. A damper door is coupled to the housing and is movable between a first position configured to restrict airflow between the refrigerator compartments and a second position configured to allow airflow between the refrigerator compartments. An actuation device is operatively coupled to said damper door. The actuation device is configured to move the damper door between the first position and the second position during an energizing cycle, and the actuation device is configured to be energized intermittently during the energizing cycle.

BACKGROUND OF THE INVENTION

This invention relates generally to damper assemblies for refrigerators, and more particularly, to damper assemblies having noise dampening features.

Known refrigerators typically regulate a temperature of a refrigerated compartment by opening and closing a damper door established in flow communication with a freezer compartment. At least some known refrigerators also operate a fan to draw cold freezer compartment air into the refrigerated compartment as needed to maintain a desired temperature in the fresh food compartment.

In known refrigerators, however, operation of the damper door may be problematic. For example, when the damper door is moved to an open position or a closed position, the damper door impacts a travel stop. The noise level of the impact is objectionable in some known dampers. Additionally, the damper door and/or the travel limits may be damaged or deteriorated over time and after multiple uses due to the force of the impact.

BRIEF DESCRIPTION OF THE INVENTION

In one aspect, a damper assembly is provided including a housing positionable between refrigerator compartments operable at different temperatures. A damper door is coupled to the housing and is movable between a first position configured to restrict airflow between the refrigerator compartments and a second position configured to allow airflow between the refrigerator compartments. An actuation device is operatively coupled to said damper door. The actuation device is configured to move the damper door between the first position and the second position during an energizing cycle, and the actuation device is configured to be energized intermittently during the energizing cycle.

In another aspect, a control system is provided for a damper assembly having a damper door movable between a first position and a second position. The control system includes an actuation device operatively coupled to the damper door and configured to move the damper door between the first position and the second position during an energizing cycle. A controller is configured to supply energy from an energy source during the energizing cycle, wherein the energy is supplied intermittently during the energizing cycle.

In a further aspect, a method is provided for operating a damper assembly having a controller, a damper door, and an actuation device operatively coupled to the damper door and configured to move the damper door between a first position and a second position during an energizing cycle. The method includes supplying energy from an energy source to the actuation device during the energizing cycle, and controlling the supply of energy from the energy source to the actuation device by intermittently energizing the actuation device during the energizing cycle.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an exemplary refrigerator.

FIGS. 2 is a perspective view of an exemplary damper assembly for the refrigerator shown in FIG. 1.

FIGS. 3 is another perspective view of the damper assembly shown in FIG. 2.

FIGS. 4 is a further perspective view of the damper assembly shown in FIG. 2.

FIG. 5 is a schematic diagram of a control system for the damper assembly shown in FIGS. 2-4.

FIG. 6 is a diagram showing an exemplary operation scheme of a control system for the damper assembly shown in FIGS. 2-4.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a perspective view of an exemplary refrigerator 100 in which exemplary embodiments of the present invention may be practiced and for which the benefits of the invention may be realized. It is appreciated, however, that the herein described methods and apparatus may likewise be practiced in a variety of refrigerating appliances with modification apparent to those in the art. Therefore, refrigerator 100 as described and illustrated herein is for illustrative purposes only and is not intended to limit the herein described methods and apparatus in any aspect.

FIG. 1 illustrates a side-by-side refrigerator 100 including a fresh food storage compartment 102 and a freezer storage compartment 104. Freezer compartment 104 and fresh food compartment 102 are arranged side-by-side. In one embodiment, refrigerator 100 is a commercially available refrigerator from General Electric Company, Appliance Park, Louisville, Ky. 40225, and is modified to incorporate the herein described methods and apparatus.

It is contemplated, however, that the teaching of the description set forth below is applicable to other types of refrigeration appliances, including but not limited to top and bottom mount refrigerators and compact refrigerators, such as refrigerators of the type having a single door with a freezer compartment received within a refrigeration compartment and having a capacity of between approximately four to six cubic feet. The herein described methods and apparatus are therefore not intended to be limited to any particular type or configuration of a refrigerator, such as refrigerator 100.

Refrigerator 100 includes multiple refrigerator compartments, such as fresh food storage compartment 102 and freezer storage compartment 104, which are contained within an outer case 106 and inner liners 108 and 110. The refrigerator compartments are operated at different temperatures. A space between case 106 and liners 108 and 110, and between liners 108 and 110, is filled with foamed-in-place insulation. Outer case 106 normally is formed by folding a sheet of a suitable material, such as pre-painted steel, into an inverted U-shape to form top and side walls of case. A bottom wall of case 106 normally is formed separately and attached to the case side walls and to a bottom frame that provides support for refrigerator 100. Inner liners 108 and 110 are molded from a suitable plastic material to form freezer compartment 104 and fresh food compartment 102, respectively. Alternatively, liners 108, 110 may be formed by bending and welding a sheet of a suitable metal, such as steel. The illustrative embodiment includes two separate liners 108, 110 as it is a relatively large capacity unit and separate liners add strength and are easier to maintain within manufacturing tolerances. In smaller refrigerators and in some compact refrigerators, a single liner is formed and a mullion spans between opposite sides of the liner to divide it into a freezer compartment and a fresh food compartment. In some compact refrigerators, a single liner is formed and a formed metal liner is attached within fresh food compartment to form freezer compartment.

A breaker strip 112 extends between a case front flange and outer front edges of liners. Breaker strip 112 is formed from a suitable resilient material, such as an extruded acrylo-butadiene-styrene based material (commonly referred to as ABS).

The insulation in the space between liners 108, 110 is covered by another strip of suitable resilient material, which also commonly is referred to as a mullion 114. Mullion 114 also preferably is formed of an extruded ABS material. Breaker strip 112 and mullion 114 form a front face, and extend completely around inner peripheral edges of case 106 and vertically between liners 108, 110. Mullion 114, insulation between compartments, and a spaced wall of liners separating compartments, sometimes are collectively referred to herein as a center mullion wall 116.

Shelves 118 and slide-out drawers 120 normally are provided in fresh food compartment 102 to support items being stored therein. A bottom drawer or pan 122 may partly form a quick chill and thaw system (not shown) and selectively controlled, together with other refrigerator features, by a microprocessor (not shown) according to user preference via manipulation of a control interface 124 mounted in an upper region of fresh food storage compartment 102 and coupled to the microprocessor. A shelf 126 and wire baskets 128 are also provided in freezer compartment 104.

Microprocessor is programmed to perform functions described herein, and as used herein, the term microprocessor is not limited to just those integrated circuits referred to in the art as microprocessor, but broadly refers to computers, processors, microcontrollers, microcomputers, programmable logic controllers, application specific integrated circuits, and other programmable circuits, and these terms are used interchangeably herein.

Freezer compartment 104 includes an automatic ice maker 129 and a through the door water and ice dispenser 130 is provided in freezer door 132. Ice maker 129 includes an ice bucket 131 for storage of ice. In smaller refrigerators and in compact refrigerators, freezer compartment 104 may not include ice maker 129 or ice dispenser 130.

Freezer door 132 and a fresh food door 134 close access openings to fresh food and freezer compartments 102, 104, respectively. Each door 132, 134 is mounted by a top hinge 136 and a bottom hinge (not shown) to rotate about its outer vertical edge between an open position, as shown in FIG. 1, and a closed position (not shown) closing the associated storage compartment. Freezer door 132 includes a plurality of storage shelves 138 and a sealing gasket 140, and fresh food door 134 also includes a plurality of storage shelves 142 and a sealing gasket 144.

In accordance with known refrigerators, refrigerator 100 also includes a machinery compartment (not shown) that at least partially contains components for executing a known vapor compression cycle for cooling air. The components include a compressor (not shown), a condenser (not shown), an expansion device (not shown), and an evaporator (not shown) connected in series and charged with a refrigerant. The evaporator is a type of heat exchanger which transfers heat from air passing over the evaporator to a refrigerant flowing through the evaporator, thereby causing the refrigerant to vaporize. The cooled air is used to refrigerate one or more refrigerator or freezer compartments via fans (not shown). Collectively, the vapor compression cycle components in a refrigeration circuit, associated fans, and associated compartments are referred to herein as a sealed system. The construction of the sealed system is well known and therefore not described in detail herein, and the sealed system is operable to force cold air through the refrigerator.

In the exemplary embodiment, the cooled air is used to refrigerate freezer compartment 104, and the cooled air is supplied to fresh food compartment 102 via a damper assembly 200 positioned between fresh food compartment 102 and freezer compartment 104. In one embodiment, damper assembly 200 is positioned in center mullion wall 116. In other embodiments, damper assembly 200 is positioned in a duct (not shown) extending between freezer compartment 104 and fresh food compartment 102. In one embodiment, a fan (not shown) is provided within or adjacent damper assembly 200 to facilitate increasing airflow through damper assembly 200. In one embodiment, a heater is provided within or adjacent damper assembly 200 to facilitate reducing or eliminating freezing of condensation on damper assembly 200. Damper assembly 200 is operated by the microprocessor when the demand for cooling in fresh food compartment changes. For example, when cooling is demanded in fresh food compartment 102, damper assembly 200 is opened and when cooling is no longer demanded in fresh food compartment, damper assembly 200 is closed.

In an alternative embodiment, damper assembly 200 is utilized to supply cooling airflow between other types of refrigerator compartments, such as, for example, a fresh food compartment and a quick chill or quick thaw compartment contained within the fresh food compartment, or a freezer compartment and a quick chill or quick thaw compartment contained within the freezer compartment. As such, damper assembly 200 is utilized to control airflow between compartments operated at different temperatures.

FIGS. 2-4 are perspective views of damper assembly 200 for refrigerator 100 shown in FIG. 1. FIG. 2 illustrates damper assembly 200 in a closed position, wherein airflow is restricted between freezer compartment 104 and fresh food compartment 102 (shown in FIG. 1). FIG. 3 illustrates damper assembly 200 in an intermediate position, wherein some airflow is allowed between freezer compartment 104 and fresh food compartment 102. Damper assembly 200 is positioned in the intermediate position during operation of damper assembly 200, such as while damper assembly 200 is moving between the opened and closed positions. FIG. 4 illustrates damper assembly 200 in an open position, wherein airflow is allowed between freezer compartment 104 and fresh food compartment 102.

In the exemplary embodiment, damper assembly 200 is a sliding gate damper. Damper assembly 200 includes a damper housing 202, a damper door 204, and an actuation device 206 for moving damper door 204 with respect to damper housing 202. Damper door 204 is moveable between a first or closed position and a second or open position.

Damper housing 202 is fabricated from a plastic material. In one embodiment, damper housing 202 includes a sound dampening material. Damper housing 202 includes a front face 210 and a rear face 212. In the exemplary embodiment, front face 210 defines a fresh food compartment side of housing 202 and rear face 212 defines a freezer compartment side of housing 210. In one embodiment, front face 210 is exposed to fresh food compartment 102. Damper door 204 extends along rear face 212, and is moveable along rear face 212 in a linear direction, such as in the direction of arrow A. In alternative embodiments, damper door 204 is moveable in a different linear direction. In other alternative embodiments, damper door 204 is rotatable.

Damper housing 202 includes travel slots 214 extending from rear face 212. Damper door 204 engages travel slots 214, and travel slots 214 define a range of motion for damper door 204 with respect to damper housing 202. Damper housing 202 includes guide members 216 that restrict movement of damper door 204 in a direction transverse from the direction of movement of damper door 204, such as in the direction of arrow B. In one embodiment, damper housing 202 includes travel limits 218 positioned generally opposed from travel slots 214. Travel limits 218 define a maximum range of motion of damper door 204. When damper door 204 is moved to either a fully open or fully closed position, damper door 204 strikes travel limit 218, causing an audible noise. The amount of noise caused is based on factors such as the velocity of damper door 204, and the force driving damper door 204 into travel limits 218. By controlling such factors, the amount of noise may be reduced.

In the exemplary embodiment, and as illustrated in FIG. 4, damper housing 202 includes a plurality of openings 220 for air to flow through damper housing 202. Openings 220 are exposed when damper door 204 is moved to the open position, as illustrated in FIG. 4. However, openings 220 are covered when damper door 204 is in the closed position, as illustrated in FIG. 2.

Damper door 204 includes a frame or body 230 having a plurality of openings 232 separated by a plurality of slats 234. Frame 230 is slidably coupled to damper housing 202 such that openings 232 are substantially aligned with openings 220 of housing 202 when damper door 204 is moved to the open position. When damper door 204 is moved to the closed position, slats 234 are substantially aligned with openings 220 of housing 202 and restrict airflow through openings 220. In the exemplary embodiment, a first end 236 of frame 230 is received in travel slots 214 and a second end 238 of frame 230 is positioned between guide members 216. In the exemplary embodiment, a mounting member 240 extends from frame 230 proximate second end 238. Mounting member 240 is coupled to actuation device 206 and converts movement of actuation device 206 to damper door 204.

Actuation device 206 is fixedly coupled to damper housing 202. Actuation device 206 includes a solenoid 250 having a plunger 252 (shown in phantom) operatively coupled to mounting member 240. In the exemplary embodiment, solenoid 250 is a dual coil solenoid configured to control linear movement of plunger 252 in a first direction, such as in the direction of arrow C, and a second direction, such as in the direction of arrow D. For example, when a first or close coil 254 is energized, plunger 252 is moved in the first direction and damper door 204 is closed. When a second or open coil 256 is energized, plunger 252 is moved in the second direction and damper door 204 is opened. When plunger 252 is moved to either a fully open or fully closed position, plunger 252 strikes a travel limit (not shown), causing an audible noise. The amount of noise caused is based on factors such as the velocity of plunger 252, and the force driving plunger 252 into the travel limit. By controlling such factors, the amount of noise may be reduced.

FIG. 5 is a schematic diagram of a control system 300 for damper assembly 200. A power source 302 is coupled to damper assembly 200 for applying voltage to, or energizing, solenoid 250 for an energizing cycle. Each energizing cycle energizes solenoid 250 for an adequate amount of time to facilitate moving damper door 204 to the first position or to the second position. A controller 304 is operatively coupled to power source 302 for controlling the supply of power from power source 302 to solenoid 250. For example, controller 304 may control an amount of voltage applied to solenoid 250 or controller may 304 control an amount of time the voltage is applied to solenoid 250, or controller 304 may control when the voltage is applied to solenoid 250. In the exemplary embodiment, each of first coil 254 and second coil 256 receive voltage from power supply 302. Only one coil 254 or 256 is energized at a time for the energizing cycle. Once the energizing cycle is over, coil 254 or 256 is de-energized and damper door 204 is either fully closed or fully opened. In the exemplary embodiment, controller 304 signals power source 302 to energize solenoid intermittently during the energizing cycle, as described below in more detail. For example, the controller 304 sends a pulse width modulated signal to power source 302 to control the energization of solenoid 250. In the exemplary embodiment, the pulse width is increased with each successive pulse during the energizing cycle.

FIG. 6 is a diagram showing an exemplary operation scheme of control system 300 during a single energizing cycle. The diagram illustrates the application of voltage 350 from power supply 302 (shown in FIG. 5) to solenoid 250 (shown in FIGS. 2-4) over a predetermined time 352. The time illustrated in FIG. 6 represents a single energizing cycle and is shown in milliseconds. Additionally, the diagram illustrates various voltage application times, shown generally at 354. It is appreciated that the voltage, the energizing cycle and the various voltage application times 354 illustrated in FIG. 6 are for illustrative purposes only, and are not intended to be limited to the voltages or times shown in FIG. 6. Rather, the voltages and times may be more or less than the voltages or times illustrated in FIG. 6.

In operation, controller 304 signals power source 302 to energize solenoid 250 intermittently during the energizing cycle. In the exemplary embodiment, power source 302 pulses solenoid 250 for a series of voltage application time 354 such that solenoid 250 is not continuously energized for the entire energizing cycle. Additionally, each voltage application time 354 is incrementally increased during the energizing cycle. For example, when the energizing cycle is initiated, a voltage is applied to solenoid 250 for a predetermined amount of time. The initial energization is a relatively short time period, as compared to other voltage application times 354. A wait time 356 is then initiated, and after a predetermined amount of time, a second energization is initiated. The second energization is applied for a longer period of time than the initial energization. Another wait time 356 is initiated. The second wait time may be equal to the first wait time, or the second wait time may be more or less than the first wait time. In the exemplary embodiment, each successive wait time is less than the previous wait time because each energization is initiated at equal intervals, such as 50 milliseconds. In the exemplary embodiment, the final energization of solenoid 250 in each energizing cycle occurs for approximately the entire interval. As such, solenoid 250 provides an adequate force to overcome a high friction force.

In use, damper door 204 resists movement while opening or closing due to friction. Friction exists between damper door 204 and damper housing 202. Additionally, friction may exist based on freezing of condensation near the interface of damper door 204 and damper housing 202. The friction force must be overcome to initiate movement of damper door 204 in either the first or second directions. Solenoid 250 forces damper door 204 to move. To overcome the friction force, solenoid 250 is energized for a minimum time. The minimum time varies based on the interaction of damper door 204 and damper housing 202 and other variables, such as an amount of freezing. As such, the minimum time may be different for each energizing cycle. By pulsing the voltage applied to solenoid 250, and by incrementally increasing the voltage application time 354 with each successive pulse, the solenoid 250 eventually overcomes the friction force and initiates movement of damper door 204. The solenoid 250 provides an initial acceleration and momentum to damper door 204, and then removes the force pushing or pulling damper door 204 open or closed. As such, damper door 204 decelerates toward travel limits 218 once voltage application time 354 is ended. Additionally, because of wait time 356, damper door 204 is not being actively moved (i.e. pushed or pulled) toward travel limit 218. As such, the force that damper door 204 engages travel limits 218 is reduced as compared to a situation wherein damper door 204 is actively being moved by solenoid 250 throughout the damper door 204 range of motion. Once damper door 204 is positioned against travel limits 218, additional energization of solenoid 250 does not cause movement of damper door 204.

A damper assembly is thus provided which functions in a cost effective and reliable manner. The damper assembly includes a dual coil solenoid that opens or closes a damper door based on a control scheme from a controller. The controller signals a power source to pulse energy to one of the coils during an energizing cycle to either open or close the damper door. The duration of energization is increased with each successive pulse to provide a force to overcome a friction force resisting movement of the damper door. Because the energy supplied to the solenoid is pulsed, the average voltage applied is reduced, thus reducing an impact force of the damper door and the plunger of the solenoid at respective travel limits. As a result, the amount of noise from the impact is reduced as compared to damper assemblies that provide a continuous voltage to the solenoid.

Exemplary embodiments of damper assemblies are described above in detail. The damper assemblies are not limited to the specific embodiments described herein, but rather, components of each damper assembly may be utilized independently and separately from other components described herein. For example, each damper assembly component can also be used in combination with other damper assembly components.

While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims. 

1. A damper assembly comprising: a housing positionable between refrigerator compartments operable at different temperatures; a damper door coupled to said housing, said damper door movable between a first position configured to restrict airflow between the refrigerator compartments and a second position configured to allow airflow between the refrigerator compartments; and an actuation device operatively coupled to said damper door, said actuation device configured to move said damper door between said first position and said second position during an energizing cycle, said actuation device configured to be energized intermittently during the energizing cycle.
 2. A damper assembly in accordance with claim 1 wherein said actuation device comprises a solenoid comprising a plunger operatively coupled to said damper door.
 3. A damper assembly in accordance with claim 1 wherein said actuation device comprises a dual coil solenoid comprising a plunger operatively coupled to said damper door wherein a first coil is energized to move said damper door in said first direction and a second coil is energized to move said damper door in said second direction.
 4. A damper assembly in accordance with claim 1, said actuation device configured to receive a voltage during the energizing cycle, wherein the voltage is pulsed during the energizing cycle.
 5. A damper assembly in accordance with claim 4 wherein the voltage is pulsed for an increasing duration during the energizing cycle.
 6. A damper assembly in accordance with claim 4 wherein the voltage is incrementally increased for each pulse during the energizing cycle.
 7. A damper assembly in accordance with claim 1, said actuation device configured to receive a pulse width modulated signal.
 8. A damper assembly in accordance with claim 7 wherein the pulse width is increased with each pulse during the energizing cycle.
 9. A damper assembly in accordance with claim 1 wherein said damper door is decelerated as said damper door moves from said first position toward said second position and said damper door is decelerated as said damper door moves from said second position toward said first position.
 10. A control system for a damper assembly having a damper door movable between a first position and a second position, said control system comprising: an actuation device operatively coupled to the damper door and configured to move the damper door between the first position and the second position during an energizing cycle; and a controller configured to supply energy from an energy source during the energizing cycle, wherein the energy is supplied intermittently during the energizing cycle.
 11. A control system in accordance with claim 10 wherein said actuation device comprises a solenoid comprising a plunger operatively coupled to the damper door.
 12. A control system in accordance with claim 10 wherein the energy supplied is pulsed to said actuation device and the duration of each successive pulse is increased during the energizing cycle.
 13. A control system in accordance with claim 10 wherein the energy supplied is pulsed to said actuation device and the voltage of each successive pulse is increased during the energizing cycle.
 14. A control system in accordance with claim 10, said controller is configured to supply a pulse width modulated signal from the energy source.
 15. A control system in accordance with claim 14 wherein the pulse width is increased with each pulse during the energizing cycle.
 16. A method of operating a damper assembly having a controller, a damper door, and an actuation device operatively coupled to the damper door and configured to move the damper door between a first position and a second position during an energizing cycle, said method comprising: supplying energy from an energy source to the actuation device during the energizing cycle; and controlling the supply of energy from the energy source to the actuation device by intermittently energizing the actuation device during the energizing cycle.
 17. A method in accordance with claim 16 wherein said controlling the supply of energy comprises pulsing energy from the energy source to the actuation device.
 18. A method in accordance with claim 16 wherein said controlling the supply of energy comprises pulsing energy from the energy source to the actuation device, wherein a duration of each successive pulse is incrementally increased.
 19. A method in accordance with claim 16 wherein said controlling the supply of energy comprises transmitting a pulse width modulated signal from a controller to the energy source.
 20. A method in accordance with claim 16 wherein said controlling the supply of energy comprises transmitting a pulse width modulated signal from a controller to the energy source, wherein the pulse width of each successive signal is incrementally increased. 